An extractor refers to an apparatus that contacts a liquid or a solid mixture with a solvent thereby being subjected to extraction. Such an extractor can be used in various arts, and particularly used in decocting an oriental medicine called Hanyak in oriental medical science. In the past, the extractor used in home was small in size. However, as extraction in large amounts increased in recent years, the extractor to be used also became large in size. A large extractor is made of a metal such as stainless steel.
It is important for an extractor that extraction should be achieved without deteriorating the extract, e.g., chemical change. Particularly, if an extractor made of a stone or a metal is used for decocting oriental medicine, the extractor has some problems in that it causes sedimentation in an extract, decreases the solubility of the extract, and causes chemical change in the extract, thereby generating side effects. Accordingly, the extractor made of stainless steel has a problem in that its quality is deteriorated.